When Do Electoral “Waves” Appear?

Something that’s been bugging me for a while is that a lot of the discussion about the 2014 elections has revolved about whether and to what extent this might be a Republican “wave” election–based on a conception of “wave” that implies it will “break” late in the contest.

Now maybe I’m oversimplifying, but my understanding of a “wave” election is one in which the national environment strongly advantages one party over the other. The “wave” is really just a term for the large harvest the “advantaged” party gleans. It doesn’t necessarily mean that at the end of the campaign one party suddenly does better than expected, though that can happen, too (in the past it often seemed to happen because of poor and limited polling).

So 2014 has had the makings of a Republican “wave” election from the get-go, because of a tilted landscape of competitive contests (especially for the Senate, which is what most people are focusing on) and a recently emerging Republican turnout advantage. Some would add “history” as a wave factor–the strong record of parties holding the White House doing poorly in second-term midterms–though that’s more of a description than an explanation of patterns. And then there are the objective conditions in the country, notably the economy, on which popular assessments at the moment are not terribly friendly to the “governing” party (defined as Democrats). You can add issue factors like the unpopularity of Obamacare if you wish.

But all these factors are already present; they’re mostly baked into the cake of this cycle. And it’s why Republicans already have a good chance of taking over the Senate. But the idea that late in the cycle they’ll get another push is entirely speculative. Will Republicans be more enthusiastic than Democrats by Election Day? Probably, but they already are. Will Obama’s approval rating be a “drag” down the stretch? Maybe, if it goes down. The same is true of the economy: it’s not helping Democrats at all at the moment, but it might well improve. Any way you slice it, though, there’s no justification for mentally adding a few points to every Republican’s share of the vote because some “wave” is going to appear right before balloting.

Now there’s one important exception to what I’ve just said. Polls without likely voter screens may well underestimate pro-Republican factors that are already present, but aren’t evident if registered voters are presumed to be equally likely to vote. The recent NBC-Marist poll of Arkansas that created such a stir earlier this week because it showed Mark Pryor with an eleven-point lead over Tom Cotton was of RVs, not LVs. So you’d be justified in mentally adjusting that lead downward a few points. But it’s important to understand that even if the “switchover” from RV to LV polls that naturally occurs later in the cycle shows Republican gains, that doesn’t mean anything is actually changing–it just means the polls are becoming more accurate. And some pollsters deploy LV screens all along.

In any event, nobody should be under the impression that late changes in 2014 contests are inevitable just because they did occur in very different circumstances in 2010. Sometimes what you see is what you get.